This Siemens EK90 saga is developing into one of real Nordic proportions...I say this because, along with other factors, I would swear that mine (and therefore A11's) are one and the same as the tube shown here in the photo : pins; internal copper wire; saucer getter, and SMOOTH silver/grey plate. I have 2 pairs - one with clear bottom and one with black - the latter mentioned by A11, just to confuse matters even more...

To add to the confusion, I have noticed OTHER Svetlana 6A2Ps that have slight ribbing on the plate...which I think are the ones you have ordered mikelap...

The internal construction of these Svetlanas certainly does appear superior to the other make(s) that are on the web.

So the plot thickens...

Now onto the sound that comes from my 'Siemens', whoever actually made them...

To strap or not to strap? This really is becoming another source of confusion (for me anyway). After finding that further burn-in with 1-7 tamed the initial 'shock' factor, I returned to non-strap and was pleased to find that Acapella 11's comparison on page 109 seemed absolutely on the ball - what really hit me straight away was a more open/airy sound, bordering almost on 'thin', compared to 'lush/heavy' 1-7 (I leave the proper terminology to A11!!). I would simply summarise the overall effect - for me - as more 'polite/refined' non-strapped, but more 'exciting' strapped.

Which do I prefer? Damned if I can yet be sure!! I think this debate could go on forever...

I envy you M that you came to your own conclusion so quickly...if only I could!

I will know tommorrow what they are will post a closeup of the plates for you to check out ya missed the mailman today finally guy from bulgaria wasnt putting me on it took less than 2 weeks from Russia was 1 month so thats great but did not get the Siemens rohre eh90 from Germany yet. and finally update for the G.E.6AV6 after sounding muffled they opened up again i must be going nuts but i did not try the Hit Ray again will take a break for a few days.

Would this be right? The 6N6P-IR. And was wondering if anyone had experience with the Sylvania EK90's because the 12AU7 Sylvania's were really really good on my previous amp and was wondering how they fared.

This forum is fascinating for me. You know, I am not an authentic "tube roller" as you are, along with many others here. Much worse, I was not really a headphone guy, I mean, not my main interest after more than 25 years in audio. By chance, I arrived into this forum and read many really good, well informed, technically correct, well written comments about the LD MKIII and tube rolling so I was inmediately interested. You know, my audio instincts told me that something was happening here, so I went for the LDMKIII and followed the advice installing some NOS Tung-Sols 6485 with the "2-7" trick. After some posts, it is confirmed that my five TS tubes are perhaps late sixties stock, very nice ones. It is a solid, durable tube made for TV sets. Burn-in of these tubes is not linear, and it is relatively long. After the first 20 hours or so, its sound become smoother, still with a prominent bass and top end, but after 60 hours the tube stabilized nicely and reached what I think is its full performance, with a balanced, detailed, full-bodied and dynamic sound. So good that I see no reason to roll them ¡¡ Is there anything out there really superior ??

To answer posts above, I don't believe anyone has tried the Sylvania EK90/6BE6, but the premium 6BY6 Sylvanias, the 5915, have been tested by a few people and reported to be top-tier, even among heptodes.

And while the TS 6485 would still be my number 1 pentode, I really do think it is worth a heptode or two to try, as some of the are truly great tubes!

To answer posts above, I don't believe anyone has tried the Sylvania EK90/6BE6, but the premium 6BY6 Sylvanias, the 5915, have been tested by a few people and reported to be top-tier, even among heptodes.

And while the TS 6485 would still be my number 1 pentode, I really do think it is worth a heptode or two to try, as some of the are truly great tubes!

To answer posts above, I don't believe anyone has tried the Sylvania EK90/6BE6, but the premium 6BY6 Sylvanias, the 5915, have been tested by a few people and reported to be top-tier, even among heptodes.

And while the TS 6485 would still be my number 1 pentode, I really do think it is worth a heptode or two to try, as some of the are truly great tubes!

Yup, those look the same as the ones around here. Their sound changes in interesting ways depending on how you strap them. I personally like them best 1-7 strapped, but I know they sound excellent unstrapped as well.

Yup, those look the same as the ones around here. Their sound changes in interesting ways depending on how you strap them. I personally like them best 1-7 strapped, but I know they sound excellent unstrapped as well.

Alright thanks pulled the trigger on it haha now awaiting my valvos and these sylvanias and currently using voshkods with stock GE tubes from LD. So I have a enough tubes to last me a long time.

Alright thanks pulled the trigger on it haha now awaiting my valvos and these sylvanias and currently using voshkods with stock GE tubes from LD. So I have a enough tubes to last me a long time.

Nice, I'm sure you'll like the Sylvanias!

Curious as to what the Valvo you got look like though, any chance you could throw in an -ebay?- link? Most Valvo 7-pin hetpodes I've seen around always seemed to have been made by Mullard or Philips; can't know for sure unless I see some factory codes...

Curious as to what the Valvo you got look like though, any chance you could throw in an -ebay?- link? Most Valvo 7-pin hetpodes I've seen around always seemed to have been made by Mullard or Philips; can't know for sure unless I see some factory codes...

I have a LD MKIV with stock tubes now so I am just starting down the road of tube collection. I have been offered a pair of NOS unused Mullard 4010's. What is a fair price to pay for those?
In following this thread for a while I see everyone getting Heptode's, are they all very similar sounding? And if I do decide to pick some up should I look for multiples instead of pairs? Possibly thinking about channel imbalance.

Just new to the tube game, sorry if these questions have been answered before but the search function on HF leaves a lot to be desired.

Got these today look to be Electronorgtecnika 6a2p otk 7 ruggerdized for military purpose i guess saucershaped will sample them in a near future where not the same tubes as advertised on the picture but for $23.00 total for 10 tubes hope they sound decent at least .